A simulation technique is described for quantifying the contribution of three-body interactions to the thermodynamical properties of coarse-grained representations of complex fluids. The method is based on a new approach for determining virial coefficients from the measured volume-dependent asymptote of a certain structural function. By comparing the third virial coefficient B for a complex fluid with that of an approximate coarse-grained model described by a pair potential, three body effects can be quantified. The strategy is applicable to both Molecular Dynamics and Monte Carlo simulation. Its utility is illustrated via measurements of three-body effects in models of star polymers and in highly size-asymmetrical colloid-polymer mixtures.
Ashton, D. J., & Wilding, N. B. (2014). Three-body interactions in complex fluids: virial coefficients from simulation finite-size effects. Journal of Chemical Physics, 140(24), 1 - 12. . https://doi.org/10.1063/1.4883718